Cardiac Arrest in an Adolescent with Pulmonary Embolism

Audience The target audience of this simulation is emergency medicine residents and medical students. The simulation is based on a real case of a 13-year-old female who presented with seizures and hypoxia and was ultimately diagnosed with pulmonary embolism. The case highlights diagnosis and management of an adolescent with new onset seizures, deterioration in status, and treatment options in pediatric cardiac arrest due to pulmonary embolism. Background Pulmonary embolism (PE) is an uncommon cause of hypoxia in children making diagnosis difficult. A study looking at 23 years of admission and autopsy data on children found the incidence of clinically significant pulmonary embolism to be 25 per 100,000.1 However, when children present to the emergency department with hypoxia and altered mental status, a diagnosis of pulmonary embolism cannot be excluded. Risk factors such as use of estrogen containing oral contraceptives, immobilization, and recent surgery should raise suspicion for pulmonary embolism in the clinically deteriorating adolescent patient.2,3 Educational Objectives By the end of the simulation, learners will be able to: 1) develop a differential diagnosis for an adolescent presenting with hypoxia and seizure-like activity 2) discuss the utility of bedside ultrasound in helping to differentiate causes of hypoxia 3) discuss management of cardiac arrest due to PE in the pediatric patient Secondary learning objectives include: 4) discuss indications for emergent use of thrombolytics and Extracorporeal Membrane Oxygenation (ECMO) while becoming aware of institution-based limitations 5) demonstrate interpersonal communication with family, nursing, pharmacy, and consultants during high stress situations. Educational Methods This is a high-fidelity simulation that allows learners to manage the diagnosis and treatment of pulmonary embolism in an adolescent patient. Participants participated in a debriefing after the simulation. Research Methods:The effectiveness of this case was evaluated by surveys given to learners after debriefing. Learners gave quantitative and qualitative results of their feedback using a 1–5 rating scale and leaving written feedback. This case was performed with residents in their first and second years of training. Results Feedback was overall positive, with many of the residents giving the case high scores on effectiveness of the simulation in their education. They enjoyed the case and reported they would feel more comfortable in a comparable situation in the future. Discussion Pulmonary embolism is an uncommon but important diagnosis for emergency medicine physicians to consider in pediatric cardiac arrest. This case has multiple parts and was based on a real case in our emergency department in which a patient presenting with new seizure-like activity followed by cardiac arrest was ultimately diagnosed with a PE. The case was well received by our learners who felt it improved their identification of this diagnosis and its management. Topics Pulmonary embolism, oral contraceptives, altered mental status, pediatric, adolescent, cardiac arrest, ECMO, thrombolytic, hypoxia, emergency medicine, medical simulation.


Linked objectives and methods:
Adolescent patients that present to the emergency department with seizure and hypoxia have a wide differential diagnosis. This patient presents with a pulmonary embolism resulting in hypoxia causing a seizure. Pulmonary embolism is typically low on the differential for adolescent patients, but some begin to take oral contraceptives soon after puberty. Learners will first be presented with a critically ill patient and need to rapidly stabilize and form a wide list of differential diagnoses (Objective 1). The patient's condition then again deteriorates, and the learners will need to complete a repeat primary survey as well as review PALS algorithms to treat cardiac arrest (Objective 3). During the resuscitation phase when learners are reviewing reversable causes of PEA (Pulseless Electrical Activity) they will need to use bedside ultrasound that will demonstrate right heart strain from a pulmonary embolism (Objective 2). To provide proper treatment, learners will have to administer thrombolytics to achieve return of spontaneous circulation (Objective 4). Learners should also discuss ECMO if it is available at their institution (Objective 4). Throughout this simulation, a family member is present and will require frequent updates and support, and learners will need to communicate with family as well as support staff and consultants (Objective 5). At the end of the simulation, learners can discuss the underlying pathophysiology of pulmonary embolism as well as their institutions' capabilities for ECMO and the closest ECMO centers (Objective 4).

Results and tips for successful implementation:
The pilot session of this simulation was performed with emergency medicine residents in their first and second years of training. The effectiveness of the case was measured using a survey completed after the debrief. After the simulation, participants were given a survey rating their understanding of pediatric cardiac arrest prior to and after the simulation lab. They were also to give qualitative feedback on how they felt the simulation went in a comments section at the end of the survey. A scale of 1-5 (where 1 is completely disagree to 5 is completely agree) was used to answer four questions as follows:

Objectives:
By the end of this simulation session, the learner will be able to: 1. develop a differential diagnosis for an adolescent presenting with hypoxia and seizure-like activity 2. discuss the utility of bedside ultrasound in helping to differentiate causes of hypoxia 3. discuss management of cardiac arrest due to PE in the pediatric patient 4. discuss indications for emergent use of thrombolytics and Extracorporeal Membrane Oxygenation (ECMO) while becoming aware of institution-based limitations 5. demonstrate interpersonal communication with family, nursing, pharmacy, and consultants during high stress situations.
2. My knowledge after the simulation lab made me more prepared to manage a pediatric patient suffering from cardiac arrest due to PE. 3. The simulation was valuable to my clinical practice. 4. After completing this simulation lab, I will change my clinical practice when it comes to rapid assessment of a crashing pediatric patient.
In total, seven residents completed the survey. All surveys were anonymous. The mode score for questions two and three was a 5 (completely agree), whereas the mode scores for questions one and four were 4 and 3. These responses suggest that while our learners felt they had a decent background knowledge of the material, the simulation was valuable to their clinical practice and prepared them to manage a similar case in the future.
Based on the comments, a longer debrief will be in place for the next round of this simulation to allow for more question time and discussion. Also, we added the location of the case and available resources (ECMO, pediatric ICU) to the introduction so our learners could act based on these parameters. The comments from learners are below: "Excellent case, I would not change much." "More discussion time, please." "Having a two-part scenario (seizure to PE arrest) is a good approach to shifting gears in a crashing patient situation." "I would appreciate more knowledge of where we were/resources available (ex-PICU availability)."

Case Description & Diagnosis (short synopsis):
A 13-year-old female presents with seizure due to hypoxia. After initial resuscitation, she goes into PEA arrest due to pulmonary embolism. The case has three stages: 1) Managing seizure followed by intubation, 2) PEA cardiac arrest with need to recognize pulmonary embolism and treat with tPA +/-ECMO, 3) post-ROSC care and disposition.

Equipment or Props Needed:
High-fidelity adolescent simulator IV pole Crash cart Phone Airway equipment.
Of note, this case could also be run using a low fidelity mannikin with task trainers for intubation and CPR. Our mannikin does not have ultrasound capabilities, and we had our learners describe how they would perform the ultrasound to get the required images.

Confederates needed:
A nurse, a parent, one person to answer phone as the consultant/pharmacy.

Background and brief information:
A 13-year-old female presents via EMS after a seizure at home after complaining of chest pain, shortness of breath, and not feeling well earlier in the day. Arrives seizing in the ED, accompanied by EMS and a parent. She has no history of seizures or recent illness.

Initial presentation: Presents via EMS, seizing on arrival.
How the scene unfolds: There are 3 stages to this simulation. Stage 1: The patient arrives seizing and will require anti-epileptics. She remains hypoxic and will need to be intubated using RSI. After intubation, she becomes bradycardic and goes into a PEA arrest, which starts Stage 2. Stage 2: PEA arrest requiring CPR and appropriate ACLS. Bedside ultrasound will assist in diagnosis of PE, and thrombolytics should be administered to achieve ROSC, and begin Stage 3. Stage 3: Patient stabilization and disposition with discussions with family members and admitting team. seizure activity. Can also provide information on new hormonal birth control recently started.
If EKG is asked, provide sinus tachycardia EKG.
If iSTAT or ABG with electrolytes asked for by participants, provide BMP and ABG results.

Two minutes after seizure No intubation
If participants fail to intubate patient while providing bag valve mask ventilations, the oxygen saturation should start to decrease to a range of 70-74% with proper ventilation at a rate of 10-14 per minute.

IV fluids
If participants choose to administer 500 -1000 ml of crystalloid IV fluids, the heart rate will decrease from 133 to 120 beats per minute.

HR 120
After ETT done HR bradycardic After successful placement of the endotracheal tube and with proper confirmation, the heart rate should become bradycardic from the tachycardia over 30 minutes, ultimately getting to a rate of 23 beats per minute and the patient will lose pulses.
HR 23, no pulse

Stage 2
Pulseless, Starts CPR Heart rate of 23 continues and participants will need to recognize the patient does not have a pulse. If using waveform capnography capabilities, this should decrease to 5 mmHg until CPR is started.
Participants should recheck endotracheal tube placement when CPR is started and begin to go through Hs and Ts in ACLS.

Atropine
If participants choose to administer Atropine 0.5 mg to 1 mg, the heart rate can increase to 30, but the patient will still not have a pulse.

Epinephrine
Consider Hs/Ts Participants should be administering epinephrine 1 mg every 3-5 minutes throughout the cardiac arrest. Heart rate can increase to 60 on monitor but no pulse will be obtained.
Ensure good quality compressions are being done at a rate of 100-120 with proper depth and recoil.
Call for bedside ultrasound while going through Hs and Ts. Provide bedside ultrasound images.
HR 60, no pulse Recognition of right heart strain tPA given Participants recognize right heart strain on ultrasound image and consider thrombolytic therapy.
Can consult pharmacy for dose; however pharmacy will inform that this is an off-label use and there is no exact dose recommendation. Pharmacy can tell participants that in this situation for adults, 25-50 mg of tPA is normally administered.
Pulse returns 3 minutes after administration (may "jump time" to simulate true onset of tPA).
HR 120 BP 90/60 RR 6 O2 90% If no tPA given after 3 rounds of ACLS Nurse suggests tPA to be given ("What do you think is going on? Is there anything else we could try?" or "Do you think a clot busting medication would work?")

Stage 3 Post-ROSC
Once ROSC is obtained, no additional changes or medications are needed.
Participants should consider contacting an ECMO consultant for the diagnosis of massive PE, and if asked for, provide a consultant.
Obtain lab work and provide labs if ordered.
May ask for chest x-ray, provide attached chest xray.

Massive Pulmonary Embolism
• Background: Pulmonary Embolism (PE) is rare in children. Children with PE can present with symptoms including chest pain, tachypnea, cough, tachycardia, dyspnea, or sudden collapse. As clot burden increases in massive PE, blood is no longer able to be transported to the lungs from the right side of the heart, leading to right heart strain and eventually right ventricular failure. 4 This process leads to fatality due to hypoxemia and obstructive shock. • Etiology: Incidence of venous thromboembolism (VTE) in children is 0.14 to 0.21 per 10,000 children in the general population. Pulmonary embolism accounts for about 15% of these cases in children. 6 Risk factors for pulmonary embolism in children include central lines, trauma, immobility, estrogen-containing contraceptives, inflammatory conditions, malignancy, heart disease, dehydration, and obesity. 5 • Diagnostic Testing: Unfortunately, D-dimer and Wells scoring tools appear to lack utility when applied to children. 5 The gold standard for testing is a CT scan with contrast assessing for pulmonary embolism. In the incident of an acutely unstable child where it is unsafe for CT imaging, bedside ultrasound can help to identify right heart strain. • Treatment Options: In massive pulmonary embolism, thrombolytic agents can be administered in children and should be used in hemodynamically unstable patients. However, there is currently no FDA approved pediatric bolus dose of alteplase or other thrombolytic drugs. Administration of thrombolytics should be done cautiously, and if possible, with consultation of a pediatric hematologist. 7 Use of ECMO should also be considered when patients are in a peri-arrest or cardiac arrest state if the patient is being resuscitated in a facility capable of emergently performing the procedure. Other treatment options for massive PE include catheter directed thrombolytics, catheter thrombectomy, and open surgical thrombectomy in more stable patients. Early consultation for these procedures in massive and submassive pulmonary embolism has potential to decrease mortality. 11

Estrogen Containing Oral Contraceptives
• Women taking estrogen-containing oral contraceptives (OCPs) have a three to five times higher risk of thromboembolism when compared to the general population. 132 smoking, obesity, and polycystic ovary syndrome (PCOS). Alternative forms of contraception should be recommended in patients with multiple risk factors. 9,10 • Overall, use of estrogen containing OCPs is still very safe in the general population. Risk stratification should be used when a gynecologist or primary provider engages in contraceptive counseling.

Other debriefing points:
If learners did not obtain medication history, consider asking, "Would there have been a benefit to getting a full medical history from the parent? When can this happen during a busy resuscitation?" If learners did not suggest ultrasound, consider asking, "Were there any other bedside tests that could have helped make the correct diagnosis?"